The original Clear started in 2005 as the TSA tested using private companies to handle trusted travelers. At its peak, it was located in 21 airports before the company’s parent company abruptly shut Clear down on June 22, 2009.

In April 2010, Alclear, LLC bought the assets of the old Clear program and re-launched it at Orlando International and Denver International airports in November 2010.

Travelers in 20 U.S. airports now have access to dedicated Clear lines, where, for $179 a year (free for children and $50 for additional family members), they can use a special line where they use a fingerprint -- no more removing government-issued ID cards -- and move onto screening.

Why should travelers pay for Clear when PreCheck is available? “Today, more than 50 percent of our customers are PreCheck eligible,” said Caryn Seidman-Becker, Clear’s CEO and a company co-founder. “Whenever I fly out of LaGuardia, I know it’s going to take me about 20 minutes to get to the airport and through security because I have Clear and PreCheck,” she said.

Both programs require travelers to apply online, then go to the nearest airport to get a background check and be fingerprinted. If accepted, a card is mailed within two weeks with a known traveler number that can be used when booking travel online via airline websites.

The Clear program gives travelers a predictable and consistent experience at airport security checkpoints, said Seidman-Becker.

“For example, I don’t have to worry about oversleeping on my early morning flights out of LaGuardia Airport because I know Clear will give me a consistent, fast and frictionless experience,” she said. “Clear leverages technology that ensures that you don’t break stride when you enter the airport. And if you get to keep your coat and shoes on with PreCheck it’s fantastic. Even if you don’t have PreCheck, you’re still getting through the line faster.”

The process to join Clear is easy. Travelers can either fill out an online application or apply in person at the nearest airport with Clear lanes. A concierge walks you through the process, which includes iris and fingerprint scans, a government ID scan and a quiz that verifies your identity. The concierge then takes travelers to the dedicated Clear line and walks them through the scanning process.

Thanks to a special deal from Delta Air Lines, which owns a minority stake in Clear, SkyMiles frequent flyer members can join for $99 a year; SkyMiles Platinum, Gold and Silver Medallion members pay $79 a year and access is free for Delta Diamond Medallion members.

And airports aren’t the only place where customers can use Clear. “Today we have lanes at the stadiums of seven different sports teams and we will be adding more, said Seidman-Becker.

Those stadiums are Denver’s Coors Field, Miami’s American Airlines Arena and Marlins Park, New York’s Citi Field and Yankees Stadium and San Francisco’s AT&T Park.

“These places look a lot like an airport, where you have tons of people coming in,” said Seidman-Becker. “If you look at a baseball stadium with a capacity of 48,000 people, 50 percent of the fans come within 30 minutes of game time. Strengthening security and giving fans a fast, frictionless experience is important.”

Clear continues to be focused on engaging in the innovation curve, said Seidman-Becker. “Having biometric identity is the beginning. We’re looking at tasks like boarding passes, building access or cruises,” she said. “When you go to visit a company in New York City, you wait in line for security and show them your driver’s license, even if you’ve visited 15 times.”

“What we love is bringing Clear to as many travelers as possible in an affordable way as possible to anyone flying no matter whether they’re flying domestic or international. Seeing is believing, so Clear is offering travelers a free one-month trial to try it out,” said Seidman-Becker.